Radio Receivers
If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of

Improving the selectivity of the receiver
Reducing the effect of noise at low modulation depths
Reducing the effect of negative-peak clipping
Improving the effectiveness of the AGC

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Radio Receivers
Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that

The receiver cannot use a phase comparator for AFC
The transmission is not compatible with A3E
Production of AGC is a rather complicated process
Adjacent-channel rejection is more difficult

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Radio Receivers
In a ratio detector

the linearity is worse than in phase discriminator
the output is twice that obtainable from a similar phase discriminator
stabilization against signal strength variations is provided
the circuit is the same as in a discriminator, except that the diodes are reversed

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Radio Receivers
Show which of the following statements about the amplitude limiter is untrue:

The circuit is always biased in class C, by virtue of the leak-type bias.
Leak-type bias must be used
The output must be tuned
When the input increases past the threshold of the limiting, the gain decreases to keep the output constant.

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